Ameliorating synthetic method of disodium pamidronate

Aim To improve the synthetic method of disodium pamidronate.Methods β-alanine was used to react with phosphorus oxychloride and phosphorous acid.First,chlorobenzene was added to the reaction;Second,a large quantity of water was adopted to wash the intermediate to get a pure pamidronic acid;Third,sodium hydroxide was solidified to get sodium salt.Result The yield was increased from 29.7% to 47.3%,and the craft was ameliorated.Conclusion The craft was ameliorated by the above method and the yied was greatly increased.